The present invention generally pertains to electronic communication system and is particularly directed to diverse-frequency remote-control communications.
Remote control communication systems are widely used for communicating command messages to a television receiver, a video recorder/player, a television descrambler, a compact-disc player and other electronic apparatus.
Information signals transmitted in remote-control communication system are subject to interference from extraneous sources. In some prior art remote-control communication systems, intermittent interference at different frequencies may be avoided by selectively modulating an information signal containing a given message onto a signal for transmission at a frequency that then is believed to be free of interference. A signal generating unit for such a remote control system includes a first signal transmitter for transmitting a first signal at a first frequency, such as an infrared (IR) frequency; a second signal transmitter for transmitting a second signal at a second frequency, such as an ultra-high frequency (UHF) that is diverse from the first frequency; means for generating an information signal containing a given message; means for modulating the first signal with the information signal; means for modulating the second signal with the information signal; and actuating means including a switch for selectively causing either the first signal or the second signal to be modulated with the information signal and transmitted. A receiver for such a remote control system includes control means for processing the given message to control a given operation of an electronic communication apparatus; means for detecting and demodulating either the first modulated signal at the first frequency or the second modulated signal at the second frequency to provide the information signal containing the given message; and a switch for enabling the receiver to detect the transmitted signal at either the first frequency or the second frequency.